Night-time monitoring of the aerosol content of the lower atmosphere by differential photometry of the anthropogenic skyglow

Night-time monitoring of the aerosol content of the lower atmosphere is a challenging task, because appropriate reference natural light sources are lacking. Here, we show that the anthropogenic night-sky brightness due to city lights can be successfully used for estimating the aerosol optical depth of arbitrarily thick atmospheric layers. This method requires measuring the zenith night-sky brightness with two detectors located at the limiting layer altitudes. Combined with an estimate of the overall atmospheric optical depth (available from ground-based measurements or specific satellite products), the ratio of these radiances provides a direct estimate of the differential aerosol optical depth of the air column between these two altitudes. These measurements can be made with single-channel low-cost radiance detectors widely used by the light pollution research community.

Automated summary

This study demonstrates that the anthropogenic night-sky brightness due to city lights can be used to estimate the aerosol optical depth of the atmosphere, providing a new possibility for night-time monitoring.